MINERAL-GEOCHEMICAL ZONALITY OF GOLDEN-BEARING WEATHERING CRUST OF THE TOM-YAYA INTERFLUVE

Abstract

The relevance. Weathering crusts of the Tom-Yaya interfluve can be the objects of commercial gold mining. Weathering crusts are widespread in the Tom-Yaya interfluve, their gold content was established, but the structure, mineral composition and geochemical features have not been studied enough.The main aim of the research is to identify mineral and geochemical zonation of weathering crusts of the Tom-Yaya interfluve to solve the genesis issues and develop the criteria for predicting their gold content.Object: weathering crusts on the rocks of the Paleozoic basement of the Tom-Yaya interfluve. Methods. Crystal morphological features of gold and satellite minerals, paragenetic associations with ore and vein minerals were analyzed microscopically under a binocular, in reflected light, chemical composition of minerals was studied by inductively coupled plasma-atomic emission mass spectrometry (ICP-AES/MS), X-ray fluorescence microscope HORIBA Scientific XGT-7200, on a scanning electron microscope TESCAN VEGA 3 SBU with EMF OXFORD X-Max 50. Reduced chemical composition of weathering products was determined by inductively coupled plasma-atomic emission mass spectrometry. Mineral composition of pelite fraction was determined by X-ray diffraction analysis using a D8 Advance diffractometer from Bruker. The authors have carried out the reduced particle size analysis of weathering products in different zones of the profile. Results. The authors identified the residual and redeposited weathering crusts in the Tom-Yaya interfluve. The weathering products are sandy-silty, clayey and gravelly-aggregate, with a predominance of sandy and silty-clayey constituents. The authors determined the composition and distribution of section clay minerals, carbonates, pyrite, gold and other minerals. Residual weathering crusts have montmorillonite-hydromica-kaolinite composition. In the structure of the complete profile, the following zones: 1) disintegration, 2) hydration and 3) hydrolysis, are distinguished. The mineral-geochemical characteristics of the isolated zones are given. Based on the abbreviated chemical analysis, the main geochemical modules were calculated.

Keywords

• residual weathering crust
• redeposited weathering crust
• gold
• mineral-geochemical zonality
• tom-yaya interfluve